(ËlÉk tÉrn) n. 1. a reading desk in a church from which the Bible lessons are read during the service. 2. a stand with a slanted top, used to hold a book, speech, etc., at the proper height for a standing reader or speaker.
How a Diamond is Formed. In order for diamond to form there must be an available source of carbon and relatively narrow ranges of temperates and pressures must align. This happens around 100 miles below the crust. Once crystalized the diamonds must be rapidly transported to the surface without undergoing substantial change.
Diamond-bearing rock is carried from the mantle to the Earth's surface by deep-origin volcanic eruptions. The magma for such a volcano must originate at a depth where diamonds can be formed â150 km (93 mi) or more (three times or more the depth of source magma for most volcanoes).